Introduction
Hello! I'm Knightwraith, a long-time lurker, though I've poked my head out one or two times before. This is my first challenge! As I understand the categories, this actually has elements of a number of them. I went with 'Legacy' as the most applicable, as there are several generations involved. You will need either Supernatural's Planter Bowls, or Into the Future's Nature's Soil line of rugs. I don't believe any other Expansion Packs are required, but I will mention elements from them here and there. Those aspects should be entirely optional, though. No mods are required, though a passing familiarity with the game's built-in cheats is. This may get a little lengthy; please bear with me. It's not really very complicated, I just like to be thorough.

Premise

Easy: It's 2077, and USA's war with China has been escalating quickly. Fortunately, you (and perhaps your family) have been pre-approved for entry into one of Vault-Tec's new smaller-scale Vaults, underground shelters designed for a small community. While you likely won't live to see the light of day again, generations from now, your descendants will emerge from the Vault, blinking in sunlight for the first time.

Hard: It's 2076, and USA's cold war with China shows every sign of turning into a hot one. Fortunately, you (and perhaps your family) have had the foresight to begin construction of a personal underground shelter, free from the interference of the government or those nutcases over at Vault-Tec. You have one year to construct your personal Vault and attract as many other like-minded souls to your project as you can before the bombs drop. Safe inside your new underground home, new generations will live out their lives, to one day emerge and repopulate a scorched Earth.

Setup

Easy: Lifespan should be set to Medium. Create your Vault Dwellers. There should be no supernatural beings, only humans, though you may save one slot for a Plumbot if you wish. You may have as many dogs or cats (no horses underground!) as you like, but they may make things more difficult. Of these seven or eight Sims, you may have two married or dating couples OR one couple with a single offspring, any age up to Teen. All other Sims (save one) should be Young Adult or Adult and single. The oldest Sim (Adult or Elder, as you see fit) should be labelled the Overseer. Sims may have any Traits, Favorites and Lifetime Wishes you like, but bear in mind they'll be trapped underground for what will likely be the rest of their lives. For added Vault-Tec realism, dress them all in identical jumpsuits, preferably blue with yellow detailing. Select one Sim (or one family) to be your 'Founder' or 'Founding Family'; this is the lineage you need to ensure survives to see the light of day.

Hard: Lifespan should be set to Medium. Create your Vault Builders. There should be no supernatural beings, only humans. You may have as many dogs or cats (no horses underground!) as you like, but they may make things more difficult. You may have a single Sim, a couple, or a couple with a single offspring any age up to Teen. Aside from the offspring (if present), your Sims should be Young Adult or Adult. Sims may have any Traits, Favorites and Lifetime Wishes you like, but bear in mind they'll only have a year on the surface. After that, they'll be trapped underground for what will likely be the rest of their lives. You'll be recruiting other Sims during gameplay, but you want to focus on keeping the lineage of your Founder or Founding Family alive.

Prologue

Easy: Move your lucky Vault Dwellers onto the largest chunk of land they can afford, then cheat for obscene amounts of money. Vault-Tec is in bed with the government, after all. Their resources are practically unlimited. Build the most opulent, luxurious underground home you can. You'll likely want multiple bedrooms and bathrooms, a nursery, perhaps an exercise room, pool, workshop, etcetera. The design and layout is up to you. Three things are required, however: 1) A way for Sims to 'Try For Baby,' 2) A hydroponics bay or gardening room, 3) An office with attached quarters for the Overseer. Feel free to build an impressive structure topside, but remember that your Sims won't be coming back up here. They have to stay below ground. A lockable door on the first underground level to separate the Sims from the stairs or ladder up might be wise. Furniture should be medium- to high-quality, and for keeping with Vault-Tec flavor, should be retro, futuristic, or future-retro. Walls and floors should look clean and sterile. Feel free to use the BuyDebug menu to get things from the future or overseas, and to populate your garden, but Special plants like life fruit or death flowers are off-limits. There should be no fire or burglar alarms. Bear in mind: Vault-Tec's Vaults were never really designed to save anybody. They were instead meant as social engineering experiments. With that in mind, think of a way to screw with your sims. Perhaps there are no showers or baths and Sims have to clean themselves at a sink. Maybe there is no way to cook food and all food must be consumed raw. Perhaps there are no beds, just nappable furniture. Whatever it is, pick one and stick with it. Make sure, however, that the Overseer's office and quarters are exempt from the experiment and have the missing equipment. Finally: Place one low-level metal spawner on the surface (I'll explain later).

When you are satisfied with the Vault, it's time to start the game. You have until midnight on this first day to get any finishing touches done. Go to the future and buy a Plumbot and chips, if you like. Buy every book in the bookstore. Buy out the grocery store of goods. Anything you can't get in Buy Mode, get now. Before midnight arrives, get everyone inside and underground. Lock the entrance so Sims don't wander topside. Lock the Overseer's office/quarters so that only they may enter. Cancel your newspaper delivery and cheat so that the Overseer has No Bills Ever. Reduce your family funds to zero. Save your game, then go to edit your town. Nuke it. Wipe out all other lots (or at least the structures on them). Now you're ready for the next section.

Hard: The prologue for hard mode is considerably longer than one day: One year (four weeks if you don't have Seasons). Move your Sim (or family) onto the empty lot of your choosing and within their price range. You may purchase an already built-up and/or furnished lot if you like, but must then remove everything on it so that you are left with an empty lot. Begin construction of your personal Vault. The entrance to the underground must be covered by a surface building, but this building should not look like a house, store, or anything that would draw attention. Unlike Vault-Tec, you're not advertising. If you bought a huge lot and are short on funds, you might be living in this topside structure for a while, but try to keep the surface structure small and unassuming. Don't worry about going big right now, just work on the basics. Though you can't cheat for money, you may still purchase things from the BuyDebug menu, so long as you have enough money that you could buy the item legitimately. You may also buy garden plants, but must use the FamilyFunds cheat to 'pay' for them: $100 for local plants and $300 for local trees, $300 for overseas plants and $500 for overseas trees. Special plants like life fruit or death flowers are off-limits. Also, since this is a private operation not run by Vault-Tec, there's no need for a way to torment your Sims. Finally: Place one low-level metal spawner on the surface (I'll explain later). When you're running out of funds for construction, it's time to start actually playing the prologue.

At least one member of your family needs to have a real job. You're going to need money and a lot of it, but you only have a year until the bombs drop. If you made a spouse, they are free to get a job or work from home as you see fit, and if you elected to have an offspring, they must attend school if they're old enough. You have two goals for the following Sim-year: 1) Expand the shelter so that it can support more Sims and be as self-sufficient as possible. 2) Convince more Sims to join your project, hopefully until you have a full 'family.' Build relationships as best you can, but be selective about who you want to join you! You must have a separate bedroom (however small) available before you invite a Sim to join you. Once you can convince another Sim to move in, you can make full use of whatever money and inventory they brought with them. You may only control Sims outside your Founder/Founding Family to get them jobs, pursue wants, or to try to get them in a relationship with other non-family Sims (you'll need a decent breeding pool, after all). Selling the metal produced by the spawner is fair game, though it won't bring much money in. Make sure to keep up on your bills; you don't want to draw attention to your Vault by having a repo man come! Likewise, there should be no fire/burglar alarms. Your Sims will have to deal with emergencies themselves. A lockable door on the first underground level to separate the Sims from the stairs or ladder up should be in place before the end of the year. Continue to build and recruit until your 'family' is full and you're satisfied with the Vault, or until the last day of the year arrives, whichever comes first.

You have until midnight on this last day to get any finishing touches done. Go to the future and buy a Plumbot and chips, if you like. Buy every book in the bookstore. Buy out the grocery store of goods. Anything you can't get in Buy Mode, get now. Before midnight arrives, get everyone inside and underground. Lock the entrance so Sims don't wander topside. Cancel your newspaper delivery and cheat so that the head of your Founding Family has No Bills Ever. Reduce your family funds to zero. Save your game, then go to edit your town. Nuke it. Wipe out all other lots (or at least the structures on them). Now you're ready for the next section.

Vault Life

Easy/Hard: The game will play out very similarly now, whether you're independent underground homesteaders or supported by Vault-Tec. You must keep your community alive for four generations. In Sims terms, this is approximately four years, or sixteen weeks if you don't have Seasons. Individual Sims may be born and die off, but keep the community alive! Specifically, keep the lineage of your Founder/Founding Family alive. You may only directly control your Founder/Founding Family and those that join the family (new offspring, new spouses, etc), with a few exceptions. You must have NO contact with the outside world (with the exception of burglars, which can't be helped). You may only control Sims outside your Founder/Founding Family to pursue wants or to try to get them in a relationship with other non-family Sims (you'll STILL need a decent breeding pool, after all). The Stir Crazy moodlet may be removed via cheating. Once per day, the head of the Founding Family or Overseer should 'do the rounds,' stopping in every room and collecting the metal from the spawner on the surface. This is for gameplay purposes only, as far as the storyline is concerned, no one leaves the Vault. This bit of metal is your only steady income. You may sell furniture, but may not sell anything crafted by sims. This tiny income may be used to continue to expand the Vault and buy more items. While you may still purchase items from the BuyDebug menu, you may no longer purchase plants. Careful management of interbreeding will be needed to make it all the way to the end (I am not, inf fact, sure it is possible- I haven't run the numbers). Breeding is the only source of new Sims. When Sims die, delete their urns/graves. If in a Vault-Tec Vault, when the Overseer dies, the next oldest Sim becomes the Overseer. If you still have living Sims after four years, consider your Vault a success.

Epilogue

As of yet, I don't have an Epilogue to the challenge. The post-nuclear wasteland of Fallout is not a pretty place, but it is recovering. Perhaps your sims will begin to rebuild, adding new lots and structures back to the town over time. Perhaps they'll become another lawless raider gang. Maybe they never made it, and the Vault is another creepy ruin for the heroes of the wastes to discover. I'm open to any thematically-appropriate continuations of the idea!

Postscript
Thanks for looking at my first challenge! If you have suggestions, questions, tweaks, or ideas, please chime in!

I immediately thought of the user-created Arcadia world for this challenge. It's small and designed well. There's even a separate downloadable Vault 102 to place in the world. It's populated above ground but it would be easy enough to delete the above ground Sims or move some of them to the vault. I would recommend not demolishing the shack structures, though, as they would be great for the emerging families later.

This looks like a lot of fun. I think I'll do a medium-strength version of the challenge where I have to invite to move in everyone I manage to befriend but I don't know exactly when that bomb is going to drop (although I will get 12 hours notice as per the rules) I'll use a random number generator each day to find out if today's the first day of the apocalypse.

Trying this with a private vault, married couple with child. Shack at the surface, all living area underground from the start. The plan for the prep year is as follows:

Week One - establish income. Basement garden, for both income and future food security. Child does lots of fishing for future use. One parent on gardening/painting, the other pushing a rabbithole career as fast as possible.

Week Four - ...? See what it looks like when it gets closer. Probably will go to the Future for gadgets.

Update: Almost at week four now. Have moved in the founder child's best mate and a promising young couple. That only leaves one free slot for the next generation, until someone dies of course. Which could be quite some time, they are all still YA. Unless there is an accident...

Just completing the final day before lockdown. The bunker is full, what with eight sims and a lifetime's worth of skill objects etc. The founder male reached the top of his career at the eleventh hour, They are pretty much set.

I am instituting a rule that all elders must eat one magic jellybean each Sunday, meaning some will die. Otherwise they will just last forever, and there will be no chance for the younger sims to breed.

Question: my sims' inventories are full of collectible goodies. Some is food - that is okay. but what about flowers, rocks etc that have not been previously sold? Strictly speaking, it seems to me that inventories should be cleared of such items at lockdown. After that, we are allowed to collect/sell from our one spawner, and sell furniture out of the bunker, as specified above.

I don't see any financial issues arising - my sims have masses of food already, and can grow as much more as they want. They have heaps of excess furniture stashed away, to use or sell later.They have everything they could want as entertainment or skill items.

I am considering getting rid of the TV after one week of lockdown - who is going to be broadcasting anyway? Radio might be believable, and computers could run as long as there is electricity. I am assuming they have a dirty big generator somewhere in the complex.

Just completing the final day before lockdown. The bunker is full, what with eight sims and a lifetime's worth of skill objects etc. The founder male reached the top of his career at the eleventh hour, They are pretty much set.

I am instituting a rule that all elders must eat one magic jellybean each Sunday, meaning some will die. Otherwise they will just last forever, and there will be no chance for the younger sims to breed.

Question: my sims' inventories are full of collectible goodies. Some is food - that is okay. but what about flowers, rocks etc that have not been previously sold? Strictly speaking, it seems to me that inventories should be cleared of such items at lockdown. After that, we are allowed to collect/sell from our one spawner, and sell furniture out of the bunker, as specified above.

I don't see any financial issues arising - my sims have masses of food already, and can grow as much more as they want. They have heaps of excess furniture stashed away, to use or sell later.They have everything they could want as entertainment or skill items.

I am considering getting rid of the TV after one week of lockdown - who is going to be broadcasting anyway? Radio might be believable, and computers could run as long as there is electricity. I am assuming they have a dirty big generator somewhere in the complex.

Ooh, good point about the Older Sims blocking creation of the next generation. I hadn't considered that. Maybe the scenario should start with a maximum of 6 slots filled, leaving two for expansion. I'll have to think on it. Meantime, your solution is a good way of representing accidental death. As for inventory items, I would say either sell them right before the final buying spree prior to lockdown, or hold on to them, maybe in a 'museum' room as relics of the past, perhaps to be 'traded' with after emerging on the surface again. As for TV and radio, it's true no one's broadcasting anymore, but your Sims might still have DVDs and CDs, or the TVs and stereos could be hooked up to a computer with music files and files of shows and movies. There are ways to justify it.
Edit: While it could be assumed there's a generator around, you could also drop some cash on solar panels or windmills if you wanted a slightly more realistic excuse for power. Of course, such topside structures might attract attention... Of course, maybe, like a Vault from the Fallout setting, these vaults are powered by a small nuclear pile. In my game, I place a hot tub on the 4th floor (down), so the hot tub 'guts' are on the fifth and final floor. I use this as my make-believe power plant and build an appropriately industrial-looking room around it.

I didn't want to put solar or windmills on the surface for just those reasons. Good idea about the hot tub. My fourth basement is basically empty so far; they don't need it for living quarters. I could redecorate it as the power and plumbing source.

Regarding elder sims, how much of a problem that is would depend on how your lifespan is tweaked. Although "Normal" in length, mine is short on early childhood and long at the end, so my elders - especially if they have high Athletic - tend to be around for ages. Not ideal in this case.

I'm still going on this when I have time. Although, it is now very wash-spin-repeat, and I doubt I will continue unto the fourth generation. However, I don't much go for generational challenges, so that's me, not the challenge itself!

I am no longer keeping the surface access locked - too annoying to unlock the doors whenever someone got stuck and reset. There's nothing up there to do, so they don't wander much, and when I notice someone heading for the ladder, I cancel their action and send them elsewhere.

In general it's all about skilling and socialising to pass the time now. The 'challenge' (and fun) for me was in prepping for lockdown. Thanks for sharing your idea!

Hey, I'm starting to run this challenge right now on hard ( by the way isn't really hard just collect everything.) and I just, literally just, made a new discovery. Some of you might know how into the future gives you what seems like an expensive grass rug. Here's the thing about it. You can literally grow anything on it. I'm serious I tried it out with a tree inside my kitchen. A TREE!! those garden pots only let small plants inside and only one per pot. Potentially, you can plant many more plants inside these patches than you could a pot. I swear it's not a jest I was looking through for a rug to put under my table ( brilliant spending, huh?) and I noticed how their at the end and their cheaper than the rugs before them. I wasn't sure if they were like the props from showtime, so I clicked on them. 'Enjoy the crunch of real grass beneath your feet or turn your living room into a full vegetable garden' that's paraphrased by the way. So I experimented with it, and decided to go all out and went with the tree. No cheats except buydebug. Guess what I'm lining my bunker with now? Just mentioning this because I saw people were only recommending garden pots they never mentioned the grass patch so for future challenges I seriously recommend these.

Yes, the grass 'rugs' are excellent for indoor gardening. One note - full-grown trees are taller than the ceiling, so they stick through. And don't like to be moved once this happens, although the moveobjects cheat will get around that.

I'm doing this challenge again for the second time (after forgetting the first one for a while, and being unable to load it up again (shmer...)) and Iâ€™m using mods for added realism. (and extra sim slots) I've just discovered that you can delete the floor of a basement level by pressing ctrl and have used this to create a little underground town. It has a cinema, semi-mall (basically just some games and a tattoo chair...), a recreation area/garden, a public pool, a 'cafeteria', and a cemetery (it's just a large two level room with lots of shelves to put everyoneâ€™s ashes, because I don't want to delete them.) it also has a stage for bands, a 'school', a dance club/bar, a bowling hall (Iâ€™m completely sure that's not the right word.) and an underground dump with bus spawners (because I don't want to let them out at all.). and I haven't even mentioned the living areas. my vault has two types of apartments. one for families, and one for single sims. the family homes have one dream pod, a bunkbed and another bed. and an empty room for personal items they might get later. and then in the downstairs area of the houses there's a television and couch and a table with chairs and a coffee machine. the other kind of apartment is just a collection of one person bedrooms with downstairs a little television area. The founders â€˜houseâ€™ is a little nicer, with a plumbot charging station, three bedrooms (two with one dreampod each, and one with two bunkbeds.) a balcony, a kitchen (WOW! (the other sims have to live off of vending machines.)), a television area, a reading area and dining area. The normal apartments have just one all-in-one bathroom per house/entire apartment complex, but the founders â€˜houseâ€™ has two. I also forgot to tell about the nursery and pet area. I sort of ran out of space and pushed them together. The top floor has a nursery with lots of cribs (I have these cc twin beds, and theyâ€™re so cute!) and the bottom floor has toys and potties and pet things, like pet beds, and bowls and other pet stuff. I have 5 pets (three cats and two dogs.) and (letâ€™s seeâ€¦ 2X8= 16+7=23-5=18) 18 sims. No plumbots yet. Iâ€™m currently in the process of nuking my town. I might post a book about the challenge on Wattpad, because I donâ€™t want to put it on my other social media. So, if I do Iâ€™ll let you know and post a link so you can follow my progress if you want to. My god this is a humongous comment. No joke, I had to fist type this all in word to check my spelling. So, thatâ€™s all. I have pictures of my Vault if you want to see it. Soâ€¦ bye!